Zusammenfassung der Ressource
Microbiology
- Fungi
- Moulds, yeast & large fungi
- Do not make their own food
- Parasitic fungi feed on living matter - athlete's foot
- Saprophytic fungi feed on dead matter - mushrooms on soil
- Moulds
- Most are mesophiles - freezing inactivates growth
- Moisture is needed for
growth
- Classification of moulds
- Phycomycetes
- Reproduce asexually & sexually
- Produce sporangium
- Thrives at 30 degrees
- E.g. Mucor & Rhizopus
- Saprophytic mould
- Reproduces asexually & sexually
- White hyphae
- Grows on bread & soil
- Saprophytic mould
- Reproduces asexually
- Fluffy white mycelium
- Grows on bread & vegetables
- Ascomycetes
- Reproduces asexually only
- Conidium develop from the hyphae
- Thrive at 20 -30 degrees
- E.g. Penicillium & Aspergillis
- Saprophytic mould - green/ blue
- Used in blue-veined cheeses & antibiotics
- Grows on cheese & bread
- Saprophytic mould - black
- Grows on fruit & vegetables
- Moulds are aerobic & need oxygen so they can grow on the surface of food
- pH levels - moulds grow in slightly acidic conditions
- Mould needs time to multiply
- Reproduction
- Sexually
- Two hyphae grow beside each other
- They fuse
together
- The dividing wall breaks down & a zygospore
develops
- Zygospore produces & stores
spores
- It has a thick wall & protects the spores
- When conditions are suitable, the spores germinate & hyphae grow & extend
out
- Spores are released into the air & the cycle begins
again
- Asexually
- A hypha grows upwards
- The head of a hypha
- Round
(sporangium)
- Chain of spores
(condium)
- The head bursts & releases spores which travel into the
air
- If a spore finds suitable conditions, new mould growth will begin
- Moulds are saprophytes & feed on dead organic matter
- Structure
- Multi-cellular fungi & can be seen on food
- Each mould begins as a spore
- Develops a thread-like filament called a hypha which grows down into the food
- Hypha grows out & branches into hyphae
- Hyphae intertwine & become a mycelium
- Bacteria
- Bacteria is classified by shape & gram staining
- Shape
- Rod (bacillus)
- Food poisoning - salmonella, listeria
- Spherical (cocci)
- Form
- Clusters: staphylococci - food poisoning
- Chains: streptococci - sore throat
- Spiral (spirilla)
- STD's - Syphilis
- Micro-organisms
- Secrete enzymes onto their food source
- These enzymes break down the food into simple compounds
- These simple compounds are absorbed through the cell wall & provide nourishment for growth
- Terminology
- Parasites
- Micro-organisms that feed on living matter - humans/animals
- Saprophytes
- Micro-organisms that feed on dead organic matter - soil, food
- Psychrophiles
- Micro-organisms that thrive at low temperatures between -5 to 20 degrees
- Mesophiles
- Micro-organisms that thrive at temperatures between 20 - 45 degrees
- Thermophiles
- Micro-organisms that thrive at temperatures between 45 - 75 degrees
- Aerobic
- Micro-organisms that need oxygen
- Pathogens
- Bacteria that cause diseases